A problem I see with your current mob is that you have too few an option of support monster and focused too much on dishing out damage. It will not bring you that far. Work on your Megan (water Mystic Witch).

Orochi leader, Lushen, Megan, and maybe Briand (wind Death Knight) if not Sophia (wind Pierret) for arena offense and defense for the mean time. Briand doesn't really fit with the team but it will help on reviving your otherwise paper-thin wind nukers. If your Sophia can bring in the pain, it can work with Orochi and Lushen. This line up is weak on fire mobs as you may notice but if I see it correctly the current meta especially on early to midgame doesn't have that many fire mob except for the notorious Arnold (fire Death Knight) which is why I though of bringing Briand along but I doubt he'll be that much help especially if you do not have a strong AOE healer. You do not have to worry about Raoq, Lushen and Orochi can bring him down without problems. If you keep seeing fire mobs in arena, go with Megan as leader then Raoq Ellin (water Amazon) and may be Luan (water Martial artist) ---- the latter though is hard to work on due to his 'broken' skills that doesn't match each other making him not as flexible as other monsters in my opinion.

I recommend that you farm for Belladeon/Darion, Bernard/Shannon and pray for better water mobs -- better if you start working on a Sigmarus (water Phoenix).

In dungeons, Briand will be of great help as well as Orochi and Megan. You will need those monsters I recommended to you plus a Veromos to auto B10 dungeons. Your current line up may possibly bring you up to B8 but it will be hard (not impossible) to make it further.